ISO 11820:2019

In-Situ Sound Attenuation Measurement of Silencers

ISO 11820 specifies the in-situ measurement method for determining the acoustic attenuation performance of silencers installed in railway ventilation ducts, brake systems, and exhaust lines. This test is critical for validating noise control equipment on operating trains and stationary installations where laboratory testing is impractical. Railway manufacturers, maintenance operators, and acoustic engineers use these measurements to verify compliance with noise regulations and to optimize silencer design. Accreditation ensures that attenuation claims are reliable and that performance targets for noise reduction are consistently achieved in real-world applications.

What it measures

  • Sound pressure level reduction across silencer (dB)
  • Attenuation performance by frequency band
  • Insertion loss of silencer in situ
  • Acoustic performance under operating conditions
  • Noise transmission loss through silencer element
🇩🇪 DIN EN ISO 11821 🇬🇧 BS EN ISO 11821 🇫🇷 NF EN ISO 11821 🇮🇹 UNI EN ISO 11821 🇪🇸 UNE EN ISO 11821 🇳🇱 NEN EN ISO 11821 🇩🇪 DIN EN ISO 3095 🇬🇧 BS EN ISO 3095 🇫🇷 NF EN ISO 3095 🇮🇹 UNI EN ISO 3095 🇪🇸 UNE EN ISO 3095 🇳🇱 NEN EN ISO 3095
1,516 Accredited labs
17 Countries

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imetrologie GmbH Institut für Metrologie und Prozesstechnologie

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DAkkS D-K-15219-01-02 Helmstadt, DE
Taupunkttemperatur fixpunktzellen Railway braking — urban guided transport Railway vehicle body structural requirem SPRT-Sensor + 3 more
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innomatec Mess- und Schnellanschluss-Systeme

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DAkkS D-K-19194-01-00 Idstein, DE
Absolutdruck p abs > 0,8 bar > 1,2 bar > 20 bar + 3 more
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iocto

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DAkkS D-K-21204-01-00 Hofheim am Taunus, DE
Taupunkttemperatur direktanzeigende −45 °C Railway vehicle body structural requirem Widerstandssensor direktanzeigende > 200 °C + 3 more
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labopart - Medizinische Laboratorien

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DAkkS D-ML-13309-01-00 Dresden, DE
Basophile Eosinophile Erythrozyten Hämatokrit Leukozyten + 3 more
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Infektiologikum Fachärzte für Innere Medizin, Mikrobiologie, Virologie und Infektionsepidemiologie sowie Laboratoriumsmedizin

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DAkkS D-ML-19652-01-00 Frankfurt, DE
Großes Blutbild TSH Immunglobulin E 25-OH-Vitamin D Vitamin B12 + 3 more
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mib Medizinisches Infektiologiezentrum Berlin

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DAkkS D-ML-13067-01-00 Berlin, DE
Basophile Eosinophile Erythrozyten Hämatokrit Leukozyten (Zellzahl) + 3 more
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qbig

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DAkkS D-K-21619-01-00 Leer, DE
Durchflussmess- 13 m³/h - Hochspannungsmessgrößen > 25 m³/h Volumendurchfluss > 40 m³/h + 3 more
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seca

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DAkkS D-K-22590-02-01 Hamburg, DE
nichtselbsttätige elektronische Waagen − Waagen
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steep GmbH EMV-Zentrum

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DAkkS D-PL-12064-01-01 Bonn, DE
DIN EN 55016-1-4 VDE 0877-16-1-4 DIN EN 55016-2-1 VDE 0877-16-2-1 DIN EN 55016-2-2 + 3 more
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synlab Medizinisches Versorgungszentrum Labor München Zentrum

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DAkkS D-ML-13149-01-00 München, DE
Blutungszeit 5-Hydroxyindolessigsäure Aminosäuren Carbohydrate-Deficient-Transferrin Everolimus + 3 more
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tech-team Kalibrierlabor

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DAkkS D-K-15210-01-00 München, DE
Gleichspannung 0,01 V Messgeräte 0,33 V 3,3 V 330 V Gleichstromstärke 30 µA + 3 more
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velotech.de

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DAkkS D-PL-17439-02-00 Schweinfurt, DE
DIN EN ISO 4210-1 DIN EN 15194: 2018 DIN 33946 DIN EN 15918 DIN EN ISO 11243 + 3 more
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wfp Institut für Wellpappenforschung und -prüfung

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DAkkS D-PL-17881-01-01 Darmstadt, DE
ISO 534 ISO 536 rs11887534 HABP2-Gen (c.1601G>A) rs7080536 ISO 1974 + 3 more
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Labor Wisplinghoff

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DAkkS D-ML-13062-01-00 Köln, DE
Liste aller Untersuchungsverfahren Webpräsenz des Medizinischen Laboratoriu Cannabinoide (Cannabinol, Cannabidiol) Cannabinoide (THC) Cannabinoide (THC-COOH) + 3 more
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Überörtliche Berufsausübungsgemeinschaft Fachärzte für Laboratoriumsmedizin und Mikrobiologie

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DAkkS D-ML-19859-01-00 Bochum, DE
Adrenalin Amiodaron, Desmethylamiodaron CDT Amiodaron, Desethylamiodaron Dopamin + 3 more
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Überörtliche Berufsausübungsgemeinschaft MVZ Eberhard & Partner Dortmund

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DAkkS D-ML-13403-01-00 Dortmund, DE
11-Desoxycortisol Acylcarnitine Agomelatin Albendazolsulfoxid a-Hydroxy-Alprazolam + 3 more
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Industries

Railway rolling stock manufacturing Train maintenance and depot operations Acoustic engineering and noise control HVAC and ventilation system design Brake system suppliers and integrators

Related Standards

  • ISO 11821 Acoustics — In-situ measurement of sound insulation of windows and façades
  • EN ISO 3095 Acoustics — Measurement of noise emitted by railbound vehicles
  • ISO 7235 Acoustics — Laboratory measurement of sound absorption coefficient of materials in impedance tubes

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